Interpretive Summary: Use of flax fiber is limited due to the retting method, which produces inconsistent and often low quality materials. Therefore, advancement of a US flax and linen industry would require an improved retting method for better raw products for textiles and composites. Research by scientists in ARS-USDA along with collaborators at Clemson University developed methods for enzyme retting at the pilot level and tested fibers and crude yarns in an attempt to identify optimal retting formulations and resultant fiber properties. Results are important in showing the properties of enzyme- retted fibers produced in pilot scale and commercially cleaned for the first time, thereby making progress towards developing a flax/linen industry for the US.

Technical Abstract:
Enzyme retting formulations consisting of Viscozyme L, a pectinase-rich commercial enzyme product, and ethylenediaminetetraacetic acid (EDTA), were tested on Ariane fiber flax and North Dakota seed flax straw residue. Flax stems that were crimped to disrupt the outer layers were soaked with various proportions of Viscozyme-EDTA solutins, retted, and then cleaned and cottonized with commercial processing equipment. Fiber properties were determined and crude test yarns were made of raw and Shirley cleaned flax fibers and cotton in various blend levels. Cleaned fibers were obtained from both seed and fiber flax types, but with variations due to treatment. Retting formulations produced fibers having different properties, with enzyme levels of 0.3% (v/v as supplied) giving finer but weaker fibers than 0.05% regardless of EDTA level. Experimental yarns of blended flax and cotton fibers varied in mass coefficient of variation, single end strength, and nep imperfections due to sample and formulation. With cost and fiber and yarn quality as criteria, results established a range in the amounts of components comprising retting formulations as a basis for further studies to optimize enzyme-retting formulations for flax. Under conditions examined herein, Viscozyme L at 0.3% (v/v) plus 25 mM EDTA produced the best test yarns and, therefore, established a base for future studies to develop commercial-grade, short staple flax fibers for use in textiles.